Heat-insulating container

ABSTRACT

A heat insulating container is provided with an outer vessel  2  and an inner vessel  1  arranged in the outer vessel  2  with a gap  3 , at least a bag  4  arranged in the gap  3 , and a reinforcement member  10  with a rigidity higher than the composition material of the bag  4 , arranged on at least one peripheral side of the bag  4 . The reinforcement member  10  extends along the edge portion of the bag  4 . The bag  4  is formed into a rectangular shape, and the reinforcement member  10  is arranged along at least two opposite sides of the bag  4 . As a protrusion of one of the inner or outer vessels engages with the cavity or the protrusion of the reinforcement member  10  of the bag  4 , the bags  4  can be easily inserted into the gap  3.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the priority benefit of Japaneseapplication serial no. 2002-266786, filed on Sep. 12, 2002.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention generally relates to a heat-insulatingcontainer applied in a freezer/refrigerator, cooler box, vacuum bottle,a heat-insulation lunch box or the like. More specifically, relates to adouble-walled heat-insulating container comprising an inner vessel andan outer vessel, wherein a heat-insulating layer is formed between theinner vessel and the outer vessel.

[0004] 2. Description of the Related Art

[0005] A heat-insulating container such as a cooler box has an outervessel and an inner vessel made of a synthetic resin. In thedouble-walled container, a gap exists between the inner vessel and theouter vessel. A bag having a barrier property is filled with a gas(hereinafter, low heat-conductivity gas) whose heat conductivity islower than air, such as krypton, xenon, argon, or a mixing gas thereof,and the bag is inserted into the gap (referring to Japan Patent No.2989447).

[0006] Although the bag of the conventional heat-insulating containercan be filled with a predetermined amount of low heat-conductivity gas,the thickness of the central portion of the bag is larger than that ofthe edge portion. When inserting the bag into the gap between the innervessel and the outer vessel, the central portion of the bag rubs againstthe sidewalls of the inner vessel and the outer vessel. The bag may notbe properly inserted into the gap up to the depth end of the gap. If thebag filled with the low heat-conductivity gas is not properly insertedinto the gap, a partial heat-insulating layer cannot be formed betweenthe inner and the outer vessels of the heat-insulating container, andthe heat-insulating performance will be adversely affected.

[0007] When the inner and outer vessels are integrally jointed bywelding, it is difficult to maintain a uniform gap width. In a case whenthe bag is inserted into a gap that is wider than a predetermined value,some unwanted space is created between the inner and outer vessels, andthe part with the larger gap may cause the heat-insulating performancebecome low. On the other hand, in a case when the bag is inserted into agap narrower than a predetermined value, this may cause the problemssuch as application of excessive force resulting in wrinkling andbending of the bag that would otherwise generate pinholes in the bag canbe avoided. Thus, the low heat-conductivity gas leaks as time goes by,and the heat-insulating performance is lowered gradually.

[0008] Particularly, if there exists a thickness difference between thecentral portion and the edge portion of the bag, the heat-insulatingcontainer becomes a polygonal shape, for example, a box of rectangularsolid shape. The edge portion that is thinner than the central portionof the bag is arranged at the corner of the polygonal solidheat-insulating container. No heat-insulating member can be arranged atthe corner, and the bag is not in contact with the inner wall of theheat-insulating container. Then, an air layer is created between the bagand the inner wall at the corner of the heat-insulating container, andthe heat-insulating performance is lowered which is not preferable.

[0009] In order to prevent the lowering of the heat-insulatingperformance, the Japanese Patent No. 2989447 discloses arranging aheat-insulating material at the corner of the heat-insulating container.However, the shape of the heat-insulating material is fixed such thatwhen an insulating material in addition to the bag are inserted into thegap of the heat-insulating container, an excessive force is exerted onthe bag. Thus, the bag is easily damaged.

SUMMARY OF THE INVENTION

[0010] The present invention is provided to solve the aforementionedproblems and it is an object of the present invention to provide aheat-insulating container featuring a long and stable heat-insulatingperformance without partially deteriorating heat-insulating performance.

[0011] The aforementioned problems are solved by providing a heatinsulating container comprising: an inner vessel and an outer vessel,wherein the inner vessel is arranged in the outer vessel with a gap; atleast a bag, arranged in the gap, wherein the gap is filled with a gaswhose heat-conductivity is lower than that of air; and a reinforcementmember, made of a material whose rigidity is higher than that of acomposition material of the bag, is arranged on at least one peripheralside of the bag.

[0012] According to one aspect of the present invention, thereinforcement member is arranged at two sides of the bag.

[0013] According to another aspect of the present invention, aprotrusion or a cavity is formed in at least one of the inner vessel andthe outer vessel, and a cavity or a protrusion corresponding to theprotrusion or the cavity of the inner or outer vessels is formed on thereinforcement member. As the protrusion or the cavity of one of theinner or outer vessels engages with the corresponding cavity or thecorresponding protrusion of the reinforcement member, the bag can beeasily inserted into the gap.

[0014] According to still another aspect of the present invention, theinner vessel and the outer vessel are formed into polygonal shapes. Eachof the bags is inserted into the gap corresponding to at least twoadjacent sides of the polygons, and a cavity or a protrusion is formedon the reinforcement member arranged onto one of the bags, and aprotrusion or a cavity corresponding to the cavity or the protrusion, isformed on the other reinforcement member arranged onto the other bag. Asthe cavity or the protrusion of one of the reinforcement member of oneof the bags engages with the corresponding protrusion or the cavity ofthe reinforcement member of the other bag, the bags can be easilyinserted into the gap.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015] While the specification concludes with claims particularlypointing out and distinctly claiming the subject matter which isregarded as the invention, the objects and features of the invention andfurther objects, features and advantages thereof will be betterunderstood from the following description taken in connection with thefollowing accompanying drawings.

[0016]FIG. 1 is a perspective view showing heat-insulating containeraccording to one embodiment of the present invention.

[0017]FIG. 2 is a perspective view showing the first example of thereinforcement structure (formed with reinforcement members) of the bag.

[0018]FIG. 3 is a perspective view showing the structure of thereinforcement member.

[0019]FIG. 4 is a partial plane view of the reinforcement member of thefirst example.

[0020]FIG. 5 is a partial plane view of the reinforcement member of thesecond example.

[0021]FIG. 6 is a perspective view showing the second example of thereinforcement structure (formed with reinforcement members) of the bag.

[0022]FIG. 7 is a perspective view showing the third example of thereinforcement structure (formed with reinforcement members) of the bag.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] The present invention will be described in detail as follows.

[0024] A heat-insulating container according to one embodiment of thepresent invention is illustrated with reference to FIGS. 1 through 5.

[0025]FIG. 1 is a perspective view showing a heat-insulating containeraccording to one embodiment of the present invention.

[0026] In this embodiment, the heat-insulating container is adouble-walled container in which an inner vessel 1 is arranged in theouter vessel 2 with a gap 3 therebetween, and a bag 4 is arranged in thegap 3.

[0027] The inner vessel 1 is made of a synthetic resin, such as ABSresin, and a metal such as stainless steel, and is shaped into arectangular solid structure having an upper opening. The outer vessel 2is made of a synthetic resin, such as ABS resin, and a metal such asstainless steel, and is shaped into a rectangular solid structure havingan upper opening.

[0028] In this embodiment, a low heat-conductivity gas whoseheat-conductivity is lower than air is filled in the heat-insulatingcontainer. The bag 4 is arranged over the gap between the whole surfacesof a sidewall 1 a of the inner vessel 1 and a sidewall 2 a of the outervessel 2 facing to the inner vessel 1. In other words, four bags 4 arerespectively arranged in the gap 3 between the four sidewalls 1 a andfour sidewalls 2 a.

[0029] A sealing member (not shown) is formed on an opening surface ofthe gap formed between the inner vessel 1 and the outer vessel 2. It ispreferable to arrange the bag filled with a low heat-conductivity gas inthe gap at the bottom part of the heat-insulating container.

[0030] A cap capable of opening or closing the upper opening of theheat-insulating container can be properly arranged in the presentinvention. It is preferred that the cap comprising an upper plate and alower plate, wherein a bag filled with a low heat-conductivity gas isarranged in the gap between the two plates or wherein a foamingheat-insulating material is arranged in the gap.

[0031] The bag 4 with a rectangular shape is formed by heat-sealingplates (made of soft material having a gas barrier property) at threesides of its periphery, such as a five-layer structured sheet made ofpolypropylene/nylon/polyethylene terephthalate /aluminum/polyethylenewherein three peripheral sides are heat-sealed to form into a bag shape.

[0032] Among the five layers, the polypropylene layer maintains thestrength of the bag 4; the nylon layer, polyethylene terephthalate andaluminum layers maintain the gas barrier property; and the polyethylenelayer seals the heat.

[0033]FIG. 2 is a perspective view showing the first example of thereinforcement structure of the bag 4.

[0034] A reinforcement member 10 whose rigidity is higher than thecomposition material of the bag 4 is arranged on at least a peripheralpart of the bag 4.

[0035] In this example, the reinforcement members 10 extend along twosides among the heat-sealed portions 4 a forming three peripheral sidesof the bag 4. The reinforcement members 10 are arranged at two sides ofthe bag 4, i.e. two sides that oppose each other among the heat-sealedportions 4 a. Moreover, the reinforcement members 10 are arranged fromthe opening portion 5 of the heat-insulating container towards thebottom portion 6. Furthermore, the reinforcement member 10 is comprisedof plates 11 with a rectangular shape wherein a hinge 11 a is formedalong the length of the reinforcement member 10, such that thereinforcement member 10 can be folded relative to the hinge 11 a.

[0036] Cavities 10 a formed into a continuous groove shape extend overthe length of the reinforcement member 10, as shown in FIG. 3. Acrossing portion 10 c is formed in the cavity 10 a at a predeterminedposition. FIG. 3 shows an example of the reinforcement member 10 whereincavities 10 a are formed. However, it is also possible to intermittentlyform a protrusion and to arrange a concave crossing portion along thelength of the reinforcement member 10.

[0037] It is preferred that the reinforcement member 10 is made of asynthetic resin or a foaming material of a synthetic resin with a lowheat-conductivity and a high mechanical strength, such as polypropyleneand polyethylene. Because the reinforcement member 10 is made of thesynthetic resin or the foaming material of which, the reinforcementmember 10 itself has a heat-insulating property.

[0038]FIG. 4 is a partial plane view of the reinforcement member of thefirst example.

[0039] In this example, the bag 4 fixed by the reinforcement member 10and the other bag 4 fixed by the reinforcement member 12 arerespectively arranged in the gap 3 corresponding to the two adjacentsurfaces among the surfaces constructing the inner vessel 1 and theouter vessel 2, as shown in FIG. 4.

[0040] A protrusion 2 d is formed on an inner surface of the sidewall 2a at a place nearby the corner 2 c of the outer vessel 2. The protrusion2 d extends from the opening portion 5 of the heat-insulating containertowards the bottom portion 6. A cavity 10 a provided at one side of thereinforcement member 10 is engaged with the protrusion 2 d. Similarly, aprotrusion 2 e is formed on an inner surface of the sidewall 2 badjacent to the sidewall 2 a. The protrusion 2 e extends from theopening portion 5 of the heat-insulating container towards the bottomportion 6. A cavity 12 a of the reinforcement member 12 is engaged withthe protrusion 2 e. The protrusions 2 d and 2 e are not necessarilyformed in the same length as the cavities 10 a and 12 a, and can beintermittently formed on the inner surfaces of the sidewalls 2 a and 2 bto partially engage with the cavities 10 a and 12 a.

[0041] At the corner of the gap 3, one of the two cavities 10 a in twosurfaces of the reinforcement member 10 which is not engaged with theprotrusion 2 d is for engaging with the protrusion 12 b of thereinforcement member 12.

[0042]FIG. 5 is a partial plane view of the reinforcement member of thesecond example.

[0043] In this example, the bag 4 fixed by the reinforcement member 13and the other bag 4 fixed by the reinforcement member 14 arerespectively arranged in the gap 3 corresponding to the two adjacentsurfaces among the surfaces constructing the inner vessel 1 and theouter vessel 2, as shown in FIG. 5.

[0044] A protrusion 2 f is formed on an inner surface of the sidewall 2a at a place nearby the corner 2 c of the outer vessel 2. The protrusion2 f extends from the opening portion of the heat-insulating containertowards the bottom portion 6. A cavity 13 a provided at one side of thereinforcement member 13 is engaged with the protrusion 2 f. Theprotrusions 2 f is not necessarily formed in the same length as thecavity 13 a, and can be intermittently formed on the inner surfaces ofthe sidewalls 2 a to partially engage with the cavity 13 a.

[0045] At the corner of the gap 3, one of the two cavities 13 a in twosurfaces of the reinforcement member 13 which is not engaged with theprotrusion 2 f is for engaging with the reinforcement member 14.

[0046]FIGS. 4 and 5 show examples that the protrusion for engaging withthe cavity of the reinforcement member is formed on the inner surface ofthe sidewalls 2 a, 2 b. However, it is also possible to form a cavityfor engaging with the protrusion of the reinforcement member on theinner surfaces of the sidewalls 2 a, 2 b from the opening portion 5 ofthe heat-insulating container towards the bottom portion 6.

[0047] Moreover, in the heat-insulating container according to theembodiment of the present invention, at a place nearby the corner 1 b atthe outer surface of the sidewall 1 a, a cavity engaged with theprotrusion of the reinforcement member or a protrusion engaged with thecavity of the reinforcement member can be formed from the openingportion 5 of the heat-insulating container towards the bottom portion 6.

[0048] Accordingly, a cavity or a protrusion is formed on at least oneof the inner vessel 1 and outer vessel 2, and a protrusion or a cavitythat corresponds to the cavity or the protrusion on the inner vessel 1or the outer vessel 2 is formed on the reinforcement member. By engagingthe protrusion at one side with the cavity at the other side, the bag 4can be fixed by the reinforcement member. When inserting the bag 4 intothe gap 3, the bag 4 can be guided by the protrusion or cavityfacilitating the insertion into the gap 3 towards the bottom portion 6through the opening portion 5 of the heat-insulating container, andproperly arrange the bag 4 in a predetermined position in the gap 3 in adirection perpendicular to the bottom portion 6.

[0049] Because the crossing portion is arranged in the cavity of thereinforcement member, when inserting the bag 4 into the gap 3, the bag 4is caught by the cavity or protrusion arranged in the inner vessel 1 orthe outer vessel 2, and therefore the bag 4 can be properly arranged andfixed in a predetermined position in the gap 3.

[0050] In a case when the protrusion is intermittently arranged on theinner vessel 1, outer vessel 2 or the reinforcement member, because thecontact area between the reinforcement member and the inner vessel 1 orthe outer vessel 2 is small, the heat-dissipation due to heat conductionfrom the inner vessel 1 towards the outer vessel 2 through thereinforcement member can be lowered.

[0051] By arranging the bag 4 fixed by two reinforcement members toengage with the reinforcement members at the corner of the gap 3corresponding to the two adjacent surfaces, the bag 4 can be properlypositioned in the gap 3. Additionally, because the reinforcement memberis made of the foaming material of the synthetic resin with a lowheat-conductivity, the heat-insulating performance at the corner of thegap 3 cannot be lowered.

[0052] A method for manufacturing a heat-insulating container accordingto one embodiment of the present invention will be describe withreference to FIGS. 1 and 2.

[0053] The Manufacture of the Bag

[0054] First, a sheet made of a soft material with a gas barrierproperty is cut into predetermined dimensions and then folded. Thefolded sheet is heat-sealed except the non-sealing edge portion to forma half-finished body of the bag. Secondly, a tube is inserted into thenon-sealed portion. The half-finished body of the bag is filled with alow heat-conductivity gas through the tube. After filling enough lowheat-conductivity gas, the non-sealed portion is then heat-sealed tocomplete the bag 4.

[0055] The Assembly of the Heat-Insulating Container

[0056] First, a plurality of through holes 4 b is formed in the bag 4 inpositions at two sides opposite to each other among the heat-sealedportions 4 a. Secondly, after fitting the protrusions 11 b of the plates11 into the through holes 4 b of the heat-sealed portions 4 a, theplates 11 are folded relative to the hinge 11 a. Two reinforcementmembers 10 respectively sandwich two opposite sides among theheat-sealed portions 4 a, such that the reinforcement members 10 arefixed onto the bag 4. When the plate 11 is folded, the protrusions 11 bare fit in the receiving portion 11 c formed in the opposite surface.Therefore, two surfaces of the heat-sealed portions 4 a are tightlyconnected with the plates 11, and the reinforcement members 10 are fixedonto the bag 4. Regarding the other fixing method, the plates 11 and theheat-sealed portions 4 a can be fixed to each other by using an adhesiveor a tape. Secondly, the bag 4 fixed by the reinforcement member 10 isinserted into the gap 3 towards the bottom portion 6 through the openingportion 5, such that a cavity or protrusion formed on the reinforcementmember along the length, engages with a protrusion or cavity formed inthe sidewall 1 a or sidewall 2 a. Similarly, the other bag 4 fixed bythe other reinforcement member 10 is inserted into the neighboringportion of the gap 3. At the corner of the gap 3, a cavity or protrusionin one of the reinforcement members 10 engages with a protrusion or acavity of the other reinforcement members 10. Accordingly, aheat-insulating container wherein four bags are arranged in the gap 3corresponding to the four sidewalls 1 a and 2 a is obtained.

[0057] As a result, in this heat-insulating container, by arranging thereinforcement members 10 at two opposite sides among the heat-sealedportions 4 a of the bag 4, the problems such as the wrinkling or bendingof the bag 4 can be prevented. Thus, the bag 4 can be inserted up to thedepth end of the gap 3.

[0058] Moreover, because the protrusions 11 b of the plates 11 fit inthe through holes 4 b of the heat-sealed portions 4 a, the bag 4 can bepositioned and fixed at a correct position relative to the reinforcementmembers 10.

[0059] In the heat-insulating container according to the embodiment ofthe present invention, each of the bags 4 is respectively inserted intothe gap 3 corresponding to the sidewalls 1 a and 2 a to form a singleheat-insulating layer. However, it is also possible to insert two ormore bags 4 by putting one upon another into the gap 3 to form aplurality of heat-insulating layers. Accordingly, even if the gap is inthe same dimension, the heat-insulating performance can be improved dueto the laminated structure. Moreover, it is also possible to use onereinforcement member 10 to laminate and fix two or more bags 4.

[0060]FIG. 6 is a perspective view showing the second example of areinforcement structure (formed with reinforcement members) of the bag4.

[0061] In this example, the reinforcement member 20 comprisesreinforcement plates 21 and 22 that are formed into C-shapes by usingbase portions 21 a, 22 a and extending portions 21 b, 22 b thatvertically extend from two ends of the base portions 21 a, 22 a. Thebase portions 21 a and 22 a are connected to each other by ahinge-connection. In this example, the reinforcement member 20 is fixedonto the heat-sealed portions 4 a corresponding to three sides of thebag 4.

[0062] In this example, a method for fixing the reinforcement members 20onto the bag 4 is described as follows.

[0063] After fitting the protrusions 21 c of the reinforcement plate 21into the through holes 4 b formed in the heat-sealed portions 4 a of thebag 4, the reinforcement member 20 is folded relative to thehinge-connection portion. The reinforcement plates 21, 22 respectivelysandwich the heat-sealed portions 4 a, such that the reinforcementmember 20 is fixed onto the bag 4. When the reinforcement member 20 isfolded, the protrusions 21 c are fit in the receiving portions 22 cformed in the surface of the reinforcement plate 22 opposite to thereinforcement plate 21. Therefore, heat-sealed portions 4 a are tightlyconnected with the reinforcement plates 21 and 22, and the reinforcementmember 20 is fixed onto the bag 4. Moreover, because the protrusions 21c of the reinforcement plate 21 fit in the through holes 4 b of theheat-sealed portions 4 a, the bag 4 can be positioned and fixed at acorrect position relative to the reinforcement member 20. Regarding toother fixing method, the reinforcement plates 21, 22 and the heat-sealedportions 4 a can be fixed onto the bag 4 by using an adhesive or a tape.

[0064] In this example, the reinforcement structure is different fromthat of the first example, such that the reinforcement member 20 isfixed onto the heat-sealed portions 4 a (edge portion) corresponding tothree sides of the bag 4, and the bag 4 is much easier to be insertedinto the gap 3 (up to the depth end of the gap 3). Because thereinforcement member 20 is fixed onto the heat-sealed portions 4 acorresponding to the three sides of the bag 4, it is hard to applyexcessive force on the bag, so that wrinkling and bending of the bagduring insertion of the bag 4 into the gap 3 do not occur.

[0065]FIG. 7 is a perspective view showing the third example of thereinforcement structure (formed with reinforcement members) of the bag4.

[0066] In this example, the reinforcement member 30 comprisesreinforcement plates 31 and 32 formed into C-shapes similar to thereinforcement members 21, 22, wherein a grid portion 32 d formed into agrid-shape with roughly the same dimensions in swelling as the gap isformed thereon, and base portions 31 a, 32 a are hinged-connected witheach other. In this example, the reinforcement member 30 is fixed ontothe heat-sealed portions 4 a corresponding to the three sides of the bag4.

[0067] Regarding this example, the method of fixing the reinforcementmember 30 onto the bag 4 is described as follows.

[0068] After fitting the protrusions 31 c formed on the reinforcementplate 31 into the through holes 4 b formed in the heat-sealed portions 4a of the bag 4, the reinforcement member 30 is folded relative to thehinge connection portion. The reinforcement plates 31, 32 respectivelysandwich the heat-sealed portions 4 a, such that the reinforcementmember 30 is fixed onto the bag 4. When the reinforcement member 30 isfolded, the protrusions 31 are fit in the receiving portions 32 c formedin the surface of the reinforcement plate 32 opposite to thereinforcement plate 31. Therefore, heat-sealed portions 4 a are tightlyconnected with the reinforcement plates 31 and 32, and the bag 4 isfixed by the reinforcement member 30. Moreover, because the protrusions31 c of the reinforcement plate 31 fit in the through holes 4 b of theheat-sealed portions 4 a, the bag 4 can be positioned and fixed at acorrect position relative to the reinforcement member 30. Thereinforcement plates 31, 32 and the heat-sealed portions 4 a arepreferably fixed onto the bag 4 by using an adhesive or a tape.

[0069] In this example, the reinforcement structure is different fromthat of the first example, such that the reinforcement member 30 isfixed onto the heat-sealed portions 4 a (edge portion) corresponding tothe three sides of the bag 4, and the bag 4 are much easier to beinserted into the gap 3 (up to the depth end of the gap 3). Because thereinforcement member 30 is fixed onto the heat-sealed portions 4 acorresponding to the three sides of the bag 4, it is hard to applyexcessive force on the bag, so that wrinkling and bending of the bagduring the insertion of the bag 4 into the gap 3 do not occur.

[0070] Furthermore, after the bag 4 is filled with a predeterminedamount of low heat-conductivity gas, the thickness of the centralportion of bag 4 becomes larger than that of the edge portion of the bag4. In the reinforcement structure of the bag 4 according to thisexample, by pressing the central portion of the bag 4 by the grid-shapedgrid portion 32 d of the reinforcement plate 32, the thickness of thebag 4 become roughly uniform. As a result, the bag 4 can be easilyinserted into the gap 3, and the partially lowered heat-insulatingperformance in the gap 3 due to the partially uneven thickness of thebag 4 can be eliminated.

[0071] In the heat-insulating container according to the embodiment ofthe present invention, the heat-insulating container is a rectangularsolid structure. However, the shape of the heat-insulating container isnot limited to this particular shape. So long as the bag fixed by thereinforcement member can be inserted into the gap of the heat-insulatingcontainer, the heat-insulating container can be formed in any shape, forexample, can be a cylindrical shape.

[0072] Practical Embodiment

[0073] The effects of the present invention can be understood withreference to the following practical embodiment referring to FIG. 1.

[0074] A rectangular solid shaped double-walled container ismanufactured by using an inner vessel 1 whose thickness is 2.0 mm and anouter vessel 2 whose thickness is 2.0 mm. The outer dimensions (thedimensions of the outline of the outer vessel 2) of the double-walledcontainer are 380 mm Width×380 mm Length×200 mm Height; the dimensionsof the outline of the inner vessel 1 are 360 mm Width×360 mm Length×360mm Height. The width of the gap 3 is 10 mm, and the volume of the innervessel 1 is about 23 liter.

[0075] A cap (not shown) made of a synthetic resin in which a 20mm-thickness foaming material is packed is installed on the uppersurface (opening portion) of the double-walled container by screws, suchthat the cap can be opened or closed by using screws.

[0076] The gap 3 is filled with a predetermined amount of lowheat-conductivity gas, and the bags 4 fixed by the reinforcement member10 are inserted into the gap 3 to obtain the heat-insulating container.

[0077] Comparison Example

[0078] A heat-insulating material made of foaming styrene is insertedinto the gap 3 of the double-walled container of the comparison examplewhose double-walled structure is manufactured in the same shape as thepractical embodiment to obtain the heat-insulating container of thecomparison example.

[0079] The heat-insulating containers of the practical embodiment andthe comparison example are filled with hot water of 95° C., and the capsare closed. After the heat-insulating containers are sealed, the twoheat-insulating containers are placed in an environment of 35° C.

[0080] After about six hours, the water temperature are checked out, itis found that in the heat-insulating container of the practicalembodiment the water temperature is about 87° C., and the watertemperature in the heat-insulating container of the comparison exampleis about 82° C.

[0081] As a result, the heat-insulating container of the practicalembodiment can be recognized as having a very good heat-insulatingperformance.

[0082] As described above, in the heat-insulating container of thepresent invention, because the bags that are filled with a lowheat-conductivity gas are fixed by the reinforcement member made of afoaming material, are inserted into the gap of the heat-insulatingcontainer, and therefore the bags can be properly inserted into the gap(up to the depth end of the gap). Moreover, during the insertion of thebag into the gap, there is no problem such as applying excessive forceon bags, so that wrinkling and bending of the bags, creating pinholes inthe bags resulting in leaking the low heat-conductivity gas do notoccur.

[0083] Accordingly, a cavity or a protrusion is formed on at least oneof the inner vessel 1 and the outer vessel 2, and a protrusion or acavity that corresponds to the cavity or the protrusion on the innervessel 1 or the outer vessel 2 is formed on the reinforcement member. Byengaging the protrusion at one side with the cavity at the other side,the bag 4 can be fixed by the reinforcement member. When inserting thebags 4 into the gap 3, the bags 4 can be guided by the protrusion orcavity to insert into the gap 3 towards the bottom portion 6 through theopening portion 5 of the heat-insulating container, and to be properlyarranged parallel to each other in predetermined positions in the gap 3.

[0084] By arranging the two bags 4 to engage with the reinforcementmembers at the corner of the gap 3 corresponding to the two adjacentsurfaces of the heat-insulating container, the bags 4 can be properlypositioned in the gap 3. Additionally, because the reinforcement membersare made of the foaming material of a synthetic resin with a lowheat-conductivity, the heat-insulating performance at the corner of thegap 3 will not be lowered.

[0085] According to above aspects, the heat-insulating container of thepresent invention has a heat-insulating effect for a long duration andstable heat-insulating performance without partially deterioratingheat-insulating performance.

[0086] While the present invention has been described with preferredembodiments, this description is not intended to limit the presentinvention. Various modifications of the embodiment will be apparent tothose skilled in the art. It is therefore contemplated that the appendedclaims will cover any such modifications or embodiments as fall withinthe true scope of the invention.

What is claimed is:
 1. A heat insulating container comprising: an innervessel and an outer vessel, wherein the inner vessel is arranged in theouter vessel with a gap therebetween; at least a bag, arranged in thegap, wherein the gap is filled with a gas whose heat-conductivity islower than that of air; and a reinforcement member, made of a materialwhose rigidity is higher than that of a composition material of the bag,arranged on at least one peripheral side of the bag.
 2. Aheat-insulating container according to claim 1, wherein thereinforcement member is arranged at two sides of the bag.
 3. Aheat-insulating container according to claim 1, further comprising: afirst protrusion or a first cavity, formed in at least one of the innervessel and/or the outer vessel; and a second cavity or a secondprotrusion corresponding to the first protrusion or the first cavity ofthe inner or outer vessels, formed on the reinforcement member, andwherein as the first protrusion or the first cavity of the inner orouter vessels engages with the second cavity or the second protrusion ofthe reinforcement member, the bag can be easily inserted into the gap.4. A heat-insulating container according to claim 2, further comprising:a first protrusion or a first cavity, formed in at least one of theinner vessel and/or the outer vessel; and a second cavity or a secondprotrusion corresponding to the first protrusion or the first cavity ofthe inner or outer vessels, formed on the reinforcement member, andwherein as the first protrusion or the first cavity of the inner orouter vessels engages with the second cavity or the second protrusion ofthe reinforcement member, the bag can be easily inserted into the gap.5. A heat-insulating container according to claim 1, wherein the innervessel and the outer vessel are formed into polygonal shapes, and eachof the bags is inserted into the gap corresponding to at least twoadjacent sides of the polygons, and wherein further comprising: a cavityor a protrusion, formed on each of the reinforcement member of each bag,wherein as the protrusion or the cavity of one of the reinforcementmember of one the bags engages with the corresponding cavity or thecorresponding protrusion of the reinforcement member of the other bag,the bags can be easily inserted into the gap.
 6. A heat-insulatingcontainer according to claim 2, wherein the inner vessel and the outervessel are formed into polygonal shapes, and each of the bags isinserted into the gap corresponding to at least two adjacent sides ofthe polygons, and wherein further comprising: a cavity or a protrusion,formed on each of the reinforcement member of each bag, wherein as theprotrusion or the cavity of one of the reinforcement member of one thebags engages with the corresponding cavity or the correspondingprotrusion of the reinforcement member of the other bag, the bags can beeasily inserted into the gap.
 7. A heat-insulating container accordingto claim 3, wherein the inner vessel and the outer vessel are formedinto polygonal shapes, and each of the bags is inserted into the gapcorresponding to at least two adjacent sides of the polygons, andwherein further comprising: a cavity or a protrusion, formed on each ofthe reinforcement member of each bag, wherein as the protrusion or thecavity of one of the reinforcement member of one the bags engages withthe corresponding cavity or the corresponding protrusion of thereinforcement member of the other bag, the bags can be easily insertedinto the gap.
 8. A heat-insulating container according to claim 4,wherein the inner vessel and the outer vessel are formed into polygonalshapes, and each of the bags is inserted into the gap corresponding toat least two adjacent sides of the polygons, and wherein furthercomprising: a cavity or a protrusion, formed on each of thereinforcement member of each bag, wherein as the protrusion or thecavity of one of the reinforcement member of one the bags engages withthe corresponding cavity or the corresponding protrusion of thereinforcement member of the other bag, the bags can be easily insertedinto the gap.